the mourners as the bodies of the u.s. ambassador and others killed in libya return to the united states. and mitt romney ramps up his criticism of the president again as the latest polls show him falling behind in several crucial states. i'm wolf blitzer. you're in "the situation room." >>> but we begin with these live pictures. look at this. this is tahrir square in cairo. these are live pictures coming in not far from the united states embassy. once again, the protests escalating even as we speak. earlier in the day it had been relatively -- keyword, relatively, quiet. now seems to be escalating for some reason. our own ben wedeman is on the ground for us. we're going to be going to him shortly. at the same time as these scenes are unfolding, there also have been frightening scenes of violence and hatred directed at the united states and others around the region. it's spreading. and u.s. officials are very worried. sources tell me they're especially concerned about today's penetration of the united states embassy in tunisia and the reports that the american school was actually burned.